Time-accurate cfd enhanced interpretation of strain-based flow measurement

ABSTRACT

A system for measuring a velocity or volumetric fluid flow rate of a fluid flow passing within a pipe includes a SONAR flow meter configured to determine a measured velocity or volumetric rate of a fluid flow passing within a pipe. The system further includes a CFD analysis device configured to produce a simulated velocity or volumetric rate of the fluid flow passing within the pipe. The system further includes a processing unit in communication with the CFD analysis device and the SONAR flow meter. The processing unit is configured to produce at least one error function based on the measured velocity or volumetric fluid flow rate and the simulated velocity or volumetric fluid flow rate, and is configured to determine an adjusted velocity or volumetric fluid flow rate using the at least one error function and the measured velocity or volumetric fluid flow rate.

This application claims priority to U.S. Patent Appln. No. 62/885,782,filed Aug. 12, 2019, and U.S. Patent Appln. No. 62/886,138, filed Aug.13, 2019, which are herein incorporated by reference in theirentireties.

BACKGROUND 1. Technical Field

This disclosure relates generally to fluid flow measurement and, moreparticularly, to strain-based fluid flow measurement for multiphasefluid systems.

2. Background Information

In certain applications, fluid flow passing within a conduit(generically referred to hereinafter as a “pipe”) may contain fluid flowdisturbances that convect at or near the average velocity of the fluidflow. These fluid flow disturbances (sometimes referred to as “turbulenteddies” or “vortical disturbances”), are coherent dynamic conditionsthat substantially decay (by a predetermined amount) over apredetermined distance (or coherence length). These coherent flowdisturbances create pressure disturbances that are detectable as afunction of strain within the pipe. The passage of coherent flowdisturbances within the pipe, and related fluid flow velocity within thepipe, can be determined using a clamp-on, strain-based sonar flow meterssometimes referred to as “passive flow meters”. These flow metersmeasure strain within the pipe at multiple axial locations and thenutilize array processing techniques to measure the speed at whichcoherent disturbances convect past the array of strain-based sensorsattached to the pipe.

For single phase, turbulent flows, the velocity of the coherent flowdisturbances can be determined and calibrated to the velocity of thefluid flow (and therefore the volumetric fluid flow rate) within thepipe. The relationship between the measured velocity of the convectiveflow disturbances and the fluid flow velocity through the pipe is afunction of many variables including sensor spacing, frequency range,Reynolds number, inlet flow conditions, and other parameters. While thedetails of the calibration process between the speed of the velocity ofthe convective flow disturbances and the volumetric fluid flow ratethrough the pipe is beyond the scope of the disclosure, strain-basedsonar meters have demonstrated accuracy to within +/−2% accuracy involumetric flow for sufficiently-developed, sufficiently turbulent,single phase fluids and sufficiently well-mixed multiphase fluids.

In some applications, an “active” SONAR meter can be used to measurevolumetric fluid flow rate within a pipe. An active SONAR meter utilizesan array of sensors (e.g., ultrasonic transducers) that transmit asignal into the fluid flow and measure the transit time (i.e., time offlight (TOF) or phase modulation) of the signal propagating through thefluid. Some active sensor arrays utilize transmitters and receiversdisposed on opposing sides of the pipe, while others utilizetransmitters and receivers disposed on the same side of the pipe. Thesignal transit time may be indicative of a coherent flow disturbanceconvecting with the fluid flow within the pipe. The velocity of thecoherent flow disturbances through the array are indicative of the fluidflow velocity within the pipe, and therefore indicative of thevolumetric fluid flow rate through the pipe.

Clamp-on SONAR based flow meters are typically able to provide a measureof the velocity at which coherent flow disturbances convect through theflow meter over a wide range of fluid flow conditions, including fluidflow that is not fully developed and is not well mixed. However, forthese types of fluid flows, the relationship between the measuredconvective speed and the volumetric flow through the pipe becomesincreasing more uncertain as the conditions depart from fully developed,well mixed, turbulent pipe flow conditions.

The ability to clamp-on and make a flow measurement is attractive formany applications for which more conventional in-line flow meters areeither not available, or are impractical due to a wide range of reasonsincluding high installation and/or maintenance costs. Additionally,clamp-on meters are often, due to necessity, installed on locationsthat: 1) do not have the desired upstream flow length required for fullydeveloped flow profiles; and 2) have multiphase flows that are notwell-mixed. Often, these non-ideal applications are the highest valueapplications for clamp-on SONAR meters due to the high cost ofalternative means to measure the process flow.

Clamp-on flow measurement for surveillance of oil and gas wells is onesuch application. Clamp-on flow measurement is typically one or twoorders of magnitude less costly than conventional well test separators.However, the accuracy of clamp-on well testing is often impaired due toan inability to ensure the fluid flow being sensed is both fullydeveloped and well-mixed. For example, well piping often does not havethe desired upstream flow lengths to ensure a fully-developed fluidflow, and typically fluid flow velocities are insufficient to ensureadequate mixing of constituents (e.g., oil, water, gas, etc.) within thefluid flow.

SUMMARY

It should be understood that any or all of the features or embodimentsdescribed herein can be used or combined in any combination with eachand every other feature or embodiment described herein unless expresslynoted otherwise.

According to an aspect of the present disclosure, a method of measuringa velocity or volumetric fluid flow rate of a fluid flow passing withina pipe includes determining a measured velocity or volumetric rate of afluid flow passing within a pipe using a SONAR flow meter; producing asimulated velocity or volumetric rate of the fluid flow passing withinthe pipe using a CFD analysis device; producing at least one errorfunction based on the measured velocity or volumetric fluid flow rateand the simulated velocity or volumetric fluid flow rate; anddetermining an adjusted velocity or volumetric fluid flow rate using theat least one error function and the measured velocity or volumetricfluid flow rate.

In any of the aspects or embodiments described above and herein, thesteps of determining the measured velocity or volumetric fluid flow rateand producing the simulated velocity or volumetric fluid flow rate areperformed for fluid flow conditions wherein the fluid flow is one orboth of not fully developed or not well mixed.

In any of the aspects or embodiments described above and herein, thestep of producing the simulated velocity or volumetric fluid flow rateincludes inputting one or more fluid flow parameter values anditeratively adjusting the one or more fluid flow parameter values todecrease a magnitude of the at least one error function.

In any of the aspects or embodiments described above and herein, the oneor more fluid flow parameter values include at least one of one or morefluid flow constituent flow rate values, one or more fluid flowconstituent properties, or any combination thereof.

In any of the aspects or embodiments described above and herein, thestep of determining the measured velocity or volumetric fluid flow rateusing the SONAR flow meter includes measuring unsteady pressuresrelating to convective flow disturbances to determine a measuredcharacteristic velocity of the convective flow disturbances. The step ofproducing the simulated velocity or volumetric fluid flow rate includes:determining a simulated characteristic velocity of the convective flowdisturbances; determining a difference between the measuredcharacteristic velocity and the simulated characteristic velocity; andadjusting a magnitude of the at least one error function to decrease thedifference between the measured characteristic velocity and thesimulated characteristic velocity.

In any of the aspects or embodiments described above and herein, themethod further includes determining a measured fluid flow pressure dropacross a length of the pipe and producing a simulated fluid flowpressure drop across the length of the pipe using the CFD analysisdevice. Producing at least one error function further includes using themeasured fluid flow pressure drop and the simulated fluid flow pressuredrop.

In any of the aspects or embodiments described above and herein, thestep of determining the measured velocity or volumetric fluid flow rateusing the SONAR flow meter includes determining the measured velocity orvolumetric fluid flow rate using “N” number of SONAR flow meters, where“N” is an integer equal to or larger than two. The step of producing theat least one error function is based on the measured velocity orvolumetric fluid flow rate from each of the “N” SONAR flow meters andthe simulated velocity or volumetric fluid flow rate.

In any of the aspects or embodiments described above and herein, each ofthe “N” number of SONAR flow meters is associated with a respectivelength of the pipe. The method further includes determining a measuredfluid flow pressure drop across a second respective length of the pipeand producing a simulated fluid flow pressure drop across the secondrespective length of the pipe. The step of producing the at least oneerror function is additionally based on the measured fluid flow pressuredrop and the simulated fluid flow pressure drop.

In any of the aspects or embodiments described above and herein, themethod further includes controlling the fluid flow passing within thepipe with a control valve based on the adjusted velocity or volumetricfluid flow rate.

According to another aspects of the present disclosure, a system formeasuring a velocity or volumetric fluid flow rate of a fluid flowpassing within a pipe includes a SONAR flow meter configured todetermine a measured velocity or volumetric rate of a fluid flow passingwithin a pipe. The system further includes a CFD analysis deviceconfigured to produce a simulated velocity or volumetric rate of thefluid flow passing within the pipe. The system further includes aprocessing unit in communication with the CFD analysis device and theSONAR flow meter. The processing unit is configured to produce at leastone error function based on the measured velocity or volumetric fluidflow rate and the simulated velocity or volumetric fluid flow rate, andis configured to determine an adjusted velocity or volumetric fluid flowrate using the at least one error function and the measured velocity orvolumetric fluid flow rate.

In any of the aspects or embodiments described above and herein, thesystem further includes a first pressure detector disposed at anupstream end of a length of the pipe and a second pressure detectordisposed at a downstream end of the length of the pipe. The firstpressure detector and the second pressure detector are configured todetermine a measured fluid flow pressure drop across the length of thepipe.

In any of the aspects or embodiments described above and herein, the CFDanalysis device is configured to produce a simulated fluid flow pressuredrop across the length of the pipe and the processing unit is configuredto produce the at least one error function additionally based on themeasured fluid flow pressure drop and the simulated fluid flow pressuredrop.

In any of the aspects or embodiments described above and herein, thesystem further includes an intentional pressure loss device disposedwithin the pipe between the first pressure detector and the secondpressure detector with respect to the fluid flow.

In any of the aspects or embodiments described above and herein, theintentional pressure loss device is a control valve.

In any of the aspects or embodiments described above and herein, thesystem further includes “N” number of SONAR flow meters configured todetermine the measured velocity or volumetric rate of the fluid flowpassing within the pipe, where “N” is an integer equal to or larger thantwo. The processing unit is configured to produce the at least one errorfunction based on the measured velocity or volumetric fluid flow ratefrom each of the “N” SONAR flow meters and the simulated velocity orvolumetric fluid flow rate.

In any of the aspects or embodiments described above and herein, each ofthe “N” number of SONAR flow meters is associated with a respectivesecond length of the pipe.

In any of the aspects or embodiments described above and herein, thesystem further includes a plurality of pressure detectors including thefirst pressure detector and the second pressure detector. The pluralityof pressure detectors is configured to determine the measured fluid flowpressure drop by performing “M” number of differential pressuremeasurements, where “M” is an integer equal to or larger than two. TheCFD analysis device is configured to produce a simulated fluid flowpressure drop corresponding to each of the “M” number of differentialpressure measurements. The processing unit is configured to produce theat least one error function using the measured fluid flow pressure dropand the simulated fluid flow pressure drop.

In any of the aspects or embodiments described above and herein, the CFDanalysis device is configured to produce the simulated velocity orvolumetric fluid flow rate by inputting one or more fluid flow parametervalues and iteratively adjusting the one or more fluid flow parametervalues to decrease a magnitude of the at least one error function.

In any of the aspects or embodiments described above and herein, theSONAR flow meter comprises multiple sensor arrays disposed around a fullcircumference of the pipe.

In any of the aspects or embodiments described above and herein, theSONAR flow meter comprises multiple sensor arrays disposed around acircumferential portion of the pipe which is less than a fullcircumference of the pipe.

The present disclosure, and all its aspects, embodiments and advantagesassociated therewith will become more readily apparent in view of thedetailed description provided below, including the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically illustrates a fluid system, in accordance with oneor more aspects of the present disclosure.

FIG. 2 illustrates a block diagram of flow measurement system, inaccordance with one or more aspects of the present disclosure.

FIG. 3 illustrates a block diagram of flow measurement system includinga simulated fluid system, in accordance with one or more aspects of thepresent disclosure.

FIG. 4 illustrates a flow chart depicting a method of measuring avelocity or volumetric fluid flow rate of a fluid flow passing within apipe, in accordance with one or more embodiments of the presentdisclosure.

DETAILED DESCRIPTION

According to an aspect of the present disclosure, a fluid flow meteringsystem and method is provided which utilizes a SONAR fluid flow meterand a time-accurate Computational Fluid Dynamics (CFD) analysis deviceconfigured to resolve length scales associated with coherent flowdisturbances convecting within a single phase fluid flow and/or amultiphase fluid flow traveling within a pipe. The CFD analysis devicemay be configured to simulate data representative of coherent flowdisturbances sensed by a SONAR flow meter; e.g., unsteady pressuresignals measured using a strain-based passive SONAR flow meter todetermine a measured characteristic velocity of the convective flowdisturbances. Thus, the CFD analysis device may produce simulated datacorresponding to a determined simulated characteristic velocity of theconvective flow disturbances. The simulated data may then be comparedwith data produced using a SONAR flow meter (i.e., “measured data”) todefine one or more error functions (or other compensation factors) thatrepresent the difference between the simulated data and measured data.The present disclosure is not limited to any particular data form forcomparison sake; e.g., data may be modeled and models compared, etc.Fluid flow parameters (e.g., fluid flow rates, etc.) that are input intothe CFD analysis device may be iteratively updated to minimize an errorfunction. Fluid flow parameters that are consistent with informationassumed known about the process fluid, and that minimize the errorfunction may be determined as a “best” solution (e.g., “best fit”) forthe fluid flow rates of the process fluid flow within the pipe.

Referring to FIGS. 1 and 4, an exemplary fluid system 100 is providedillustrating a fluid flow 104 passing within a pipe 102. In order tomeasure a velocity or volumetric fluid flow rate (hereinafter “flowrate”) of the fluid flow 104 within the pipe 102, the fluid system 100may include at least one SONAR flow meter 106 in communication with anexterior surface of the pipe 102 (Step 402 of Method 400). Aspects ofthe present disclosure are well-suited for, but not limited to,strain-based clamp-on SONAR flow meter multiphase fluid well testing.However, it should be understood that aspects of the present disclosureare also applicable to flow meters having alternative configurations. Invarious embodiments, the SONAR flow meter 106 may be disposed about afull circumference of the pipe 102 or may be limited to acircumferential region. The SONAR flow meter 106 may include multiplesensor arrays of full or limited circumferential extent over a same orsimilar axial location with respect to the orientation of the pipe 102.For example, sensor arrays of the SONAR flow meter 106 at the top andbottom of a horizontal section of the pipe 102 may provide a measuredindication of the convective flow rate of the fluid flow 104 along thetop and bottom of the pipe 102, which top and bottom portions of thefluid flow 104 can differ significantly for multiphase fluid flows.

As shown in FIG. 1, the at least one SONAR flow meter 106 may include aplurality of SONAR flow meters (e.g., “N” number of flow meters), suchas a first SONAR flow meter 106A and a second SONAR flow meter 106B,configured to measure a flow rate of the fluid flow 104 at a respectiveplurality of positions along a length 108 of the pipe 102. For example,the first SONAR flow meter 106A may extend along a first sub-length 108Aof the pipe 102 while the second SONAR flow meter 106B may extend alonga second sub-length 108B of the pipe 102.

In various embodiments, the fluid system 100 may include a plurality ofpressure detectors 114 configured to measure a pressure of the fluidflow 104 at a plurality of respective positions and, thereby, determinea differential pressure (e.g. a pressure drop) across the length 108 ofthe pipe 102. As shown, for example, in FIG. 1, the plurality ofpressure detectors 114 may include a first pressure detector 114Alocated at a first end 110 (e.g., upstream end) of the length 108 of thepipe 102 and a second pressure detector 114B located at a second end 112(e.g., downstream end) of the length 108 of the pipe 102. As shown, forexample, in FIG. 1, the pressure detectors 114A, 114B may encompass oneor more SONAR flow meters such as the SONAR flow meters 106A, 106B withrespect to the fluid flow 104. However, in various embodiments, a firstlength of the pipe 102 may be associated with the SONAR flow meter 106,while a second length of the pipe 102, different than the first lengthof the pipe 102, may be associated with the plurality of pressuredetectors. In various embodiments, the plurality of pressure detectors114 may include greater than two pressure detectors such that theplurality of pressure detectors 114 is configured to perform “M” numberof differential pressure measurements.

In various embodiments, the fluid system 100 may include an intentionalpressure loss device such as, for example, a control valve 116, aventuri, or another device configured to cause a substantial decrease influid pressure at a position within the pipe 102. As shown in FIG. 1,the fluid system 100 may include the control valve 116 at a positionalong the length 108 of the pipe 102. In various embodiments, thecontrol valve 116 may be located between the first SONAR flow meter 106Aand the second SONAR flow meter 106B and/or between the first pressuredetector 114A and the second pressure detector 114B, with respect to thefluid flow 104, however, no such configuration is required.

It should be understood that the illustrated fluid system 100 isprovided for the purpose of describing the operation of the SONAR flowmeter 106 and the plurality of pressure detectors 114 and that aspectsof the present disclosure may be applicable to many differentconfigurations of fluid systems. The illustrated length 108 of the pipe102 may represent all or only a portion of a fluid system which mayinclude additional flow meters, pressure detectors, control valves,pumps, etc.

Referring to FIGS. 1-4, a CFD analysis device 200 may be used to producea time-resolved CFD simulated flow rate of the fluid flow 104 passingwithin the pipe 102 (Step 404 of Method 400). In other words, the CFDanalysis device 200 may simulate the flow conditions associated with afluid system, such as the fluid system 100 described above, to determinethe simulated flow rate of the fluid flow 104 at one or more positionswithin a simulated pipe 202 corresponding to the pipe 102. As shown inFIG. 3, the CFD analysis device 200 may determine a simulated flow rateFl, F2 for a fluid flow of the simulated pipe 202 at a pipe 202 locationcorresponding to a location of the SONAR flow meter 106, 106A, 106B withrespect to the pipe 102. Similarly, the CFD analysis device 200 maydetermine simulated pressures P1, P2 for a fluid flow of the simulatedpipe 202 at a pipe 202 location corresponding to a location of theplurality of pressure detectors 114, 114A, 114B with respect to the pipe102. The CFD analysis device 200 may, therefore, determine adifferential pressure DP across the simulated pipe 202 length.

The system may include a processing unit 300 configured to perform analgorithm described herein and/or effect operation of some or all of thedevices described herein. The processing unit 300 may include any typeof computing device, computational circuit, or any type of process orprocessing circuit capable of executing a series of instructions thatare stored in memory. The processing unit may include multipleprocessors and/or multicore CPUs and may include any type of processor,such as a microprocessor, digital signal processor, microcontroller, orthe like. In some embodiments, the CFD analysis device 200 may beintegral with the processing unit 300. In some embodiments, the CFDanalysis device 200 may be independent of, but in communication with,the processing unit 300. In some embodiments, the CFD analysis device200 may be integral with the SONAR flow meter 106 and/or the pluralityof pressure detectors 114. In some embodiments, the CFD analysis device200 may be independent of, but in communication with, the SONAR flowmeter 106 and/or the plurality of pressure detectors 114. In someembodiments, the processing unit 300 may be integral with the SONAR flowmeter 106 and/or the plurality of pressure detectors 114. In someembodiments, the processing unit 300 may be independent of, but incommunication with, the SONAR flow meter 106 and/or the plurality ofpressure detectors 114.

In some embodiments, aspects of the present disclosure may allow theprocessing unit 300 to utilize a measured velocity of convective flowdisturbances, determined by the SONAR flow meter 106, and a simulatedvelocity of convective flow disturbances, determined using the CFDanalysis device 200, to define an error function 302, as shown below inEquation 1 (Step 406 of Method 400). The measured and simulatedvelocities may, in turn, be used to determine respective measured andsimulated volumetric flow rates of the fluid flow 104. As shown, forexample, in FIG. 3, fluid flow parameter values such as one or moreconstituent flow rate values of oil, water and gas within the fluid flow(e.g., Q_(gas), Q_(liq)), one or more fluid flow constituent properties(e.g., density, temperature, etc.), or any combination thereof,initially input into the CFD analysis device 200, may be iterativelyadjusted to decrease a magnitude of the error function 302. Theaforesaid fluid flow parameters may be constrained to be consistent withother fluid flow parameters assumed to be known about the process fluid.These known parameters may be, for example, water cut, gas-oil ratio,produced oil, gas, and water properties.

error=α₁(V _(sonar) _(measured) −V _(sonar) _(CFD) )²   Equation 1

The ability of the present disclosure to accurately determine multiphaseflow rates may be improved further by incorporating more information inthe optimization process. For example, pressure loss data representativeof a pressure loss over a section of piping (e.g., the simulateddifferential pressure DP) may provide another basis to compare measureddata versus simulated data (produced by the CFD analysis device 200)over a range of flow conditions. The pressure loss may or may not beproduced by a simulated intentional pressure loss device 216corresponding to the intentional pressure loss device (e.g., the controlvalve 116) of the fluid system 100. In various embodiments, the errorfunction 302 can be defined to include contributions from 1) thedifference in the measured and the CFD-simulated convection velocity and2) the difference between the measured and CFD-simulated pressure dropover a section of the pipe 102, 202, as shown in Equation 2.

error=α₁(V _(sonar) _(measured) −V _(sonar) _(CFD) )²+α₂(DP_(measured)−DP _(CFD))²   Equation 2

The ability of the present disclosure to accurately determine fluid flowrates may also be improved further by utilizing a plurality of SONARflow meters 106 at locations of the pipe with different operatingconditions including pressure, cross sectional area, proximity to flowrestrictions/expansion, and/or different flow orientation (i.e. flowupwards, downwards, horizontal, or any orientation in between). Anexample of an error function 302 for “N” SONAR meters 106 and “M”differential pressure measurements provided by the plurality of pressuredetectors 114 (where “N” and “M” are integers, equal to or larger thantwo, that may or may not equal one another) is shown in Equation 3:

$\begin{matrix}{{error} = {{\sum_{i = 1}^{N}{\alpha_{i}( {V_{{sonar}_{{measured}_{i}}} - V_{{sonar}_{{CFD}_{i}}}} )}^{2}} + {\sum_{j = 1}^{M}{\alpha_{j}( {{DP}_{{measured}_{j}} - {DP}_{{CFD}_{j}}} )}^{2}}}} & {{Equation}\mspace{14mu} 3}\end{matrix}$

Each different operating condition for which a SONAR flow meter 106records and characterizes the unsteady pressure field and for which theCFD analysis device 200 simulates the unsteady pressure field becomes anadditional comparison that can improve the fidelity of theinterpretation.

Once the error function 302 has been determined by the processing unit300, the processing unit 300 may further determine an adjusted flow rate304 using the error function 302 and the measured flow rate provided bythe SONAR flow meter 106 (Step 408 of Method 400). The error function302 used to determine the adjusted flow rate 304 may be at least oneerror function, however, a plurality of unique error functions may beused to determine the adjusted flow rate 304. The error function 302 maybe an initial error function, a “best fit” error function, or an errorfunction corresponding to any number of iterations, as discussed above.The adjusted flow rate 304 may represent a more accurate measurement ofthe flow rate of the fluid flow 104 which accounts for undeveloped fluidflows and/or incomplete mixing of constituents (e.g., oil, water, gas,etc.) within the fluid flow 104. The adjusted flow rate 304 may,therefore, provide an improved ability to control the fluid flow 104within the pipe 102 (Step 410 of Method 400). For example, the fluidflow 104 passing within the pipe 102 may be controlled based on theadjusted flow rate 304 by the control valve 116 and/or by one or moreadditional valves, pumps, or other flow control devices within the fluidsystem 100.

Time-resolved CFD simulations capable of simulating convective unsteadypressure fields with sufficient accuracy to be employed iteratively inthe methods described herein may require significant computationalresources. In various embodiments, it may be possible to produce the CFDsimulated data substantially in real time with the measured dataproduced by the SONAR flow meter 106. However, it is also contemplatedthat the computational resources which may be necessary to produce theCFD simulated data may not be available contemporaneously with themeasured data from the SONAR flow meter 106 for various reasons; e.g.,location of the SONAR flow meter 106, the environment surrounding theSONAR flow meter 106, the amount of time required to produce the CFDsimulated data, etc. In these instances, aspects of the presentdisclosure contemplate that the CFD simulated data may be producednon-contemporaneously with the measured data from the SONAR flow meter106, and interpretation/analysis of the two may be performed as aprocess distinct from the collection of the measured data from the SONARflow meter 106. This may be particularly true in those embodimentswherein multiple SONAR flow meters are utilized, each at a differentpipe location having different operating conditions as described above.

Aspects of the present disclosure also contemplate that the aforesaidmeasurement of fluid flow parameters (convective flow disturbancevelocities determined by the SONAR flow meter 106, fluid flow pressuremeasurements, etc.) may be performed at a first location (e.g., in thefield) and the data representative of those measurement may be sent to asecond location (e.g., a field office, etc.) remote from the firstlocation, and the interpretation/analysis of the two data sets may beperformed at the second location.

In these applications, fluid flow parameters may be recorded for a welloperating in an essentially time-stationary manner (i.e., steady stateproduction). Both the actual well production (i.e., the measured data)and CFD simulations will, in general, exhibit time-varying, yettime-stationary, conditions. The term “time-stationary” used hereinrefers to processes that have sufficiently constant time averagedproperties. For example, a well could exhibit somewhat random orperiodic flow parameter variations on a short time scale, for exampleseveral seconds or minutes, but the same flow parameter value may beessentially constant when viewed over a longer period of time such as aday or a week. For these conditions, time averaged values of themeasured and simulated SONAR and/or differential pressure data can beused for the optimization process. The recorded data and any informationregarding any known aspects of the fluid flow (e.g., water cut, oil-gasratio, etc.) may be supplied, along with the pipe 102 geometry forpost-processing to implement the CFD based optimized interpretation ofthe measured data in terms of gas, oil and water rates.

One or more of the fluid properties, pipe geometry, piping geometry, andan initial estimate of the multiphase flow rates (and any otherapplicable parameters) may then be used to produce at least an initialCFD simulation, which in turn may be used to produce at least an initialerror function 302. Fluid flow parameters (e.g., gas, oil, and waterflow rates, etc.) along with other unknown parameters may then be variedusing an optimization algorithm to minimize the error function 302. Thefluid flow parameters (e.g., gas, oil, and water flow rates, etc.) thatdecrease the error function to an acceptable form (e.g., minimize theerror function) represent the “best fit” of the SONAR flow meter 106 andother information in terms of the oil, water, and gas flow rates. Theresults of the optimization may be reported via a “well test report”306. Aspects of the present disclosure may be applied to any single ormultiphase flow through any piping network.

It is noted that various connections are set forth between elements inthe following description and in the drawings (the contents of which areincluded in this disclosure by way of reference). It is noted that theseconnections are general and, unless specified otherwise, may be director indirect and that this specification is not intended to be limitingin this respect. A coupling between two or more entities may refer to adirect connection or an indirect connection. An indirect connection mayincorporate one or more intervening entities or a space/gap between theentities that are being coupled to one another.

Furthermore, any reference to singular includes plural embodiments, andany reference to more than one component or step may include a singularembodiment or step. Also, any reference to attached, fixed, connected orthe like may include permanent, removable, temporary, partial, fulland/or any other possible attachment option. Additionally, any referenceto without contact (or similar phrases) may also include reduced contactor minimal contact.

Furthermore, no element, component, or method step in the presentdisclosure is intended to be dedicated to the public regardless ofwhether the element, component, or method step is explicitly recited inthe claims. No claim element herein is to be construed under theprovisions of 35 U.S.C. 112(f) unless the element is expressly recitedusing the phrase “means for.” As used herein, the terms “comprises”,“comprising”, or any other variation thereof, are intended to cover anon-exclusive inclusion, such that a process, method, article, orapparatus that comprises a list of elements does not include only thoseelements but may include other elements not expressly listed or inherentto such process, method, article, or apparatus.

What is claimed is:
 1. A method of measuring a velocity or volumetricfluid flow rate of a fluid flow passing within a pipe, comprising:determining a measured velocity or volumetric rate of a fluid flowpassing within a pipe using a SONAR flow meter; producing a simulatedvelocity or volumetric rate of the fluid flow passing within the pipeusing a CFD analysis device; producing at least one error function basedon the measured velocity or volumetric fluid flow rate and the simulatedvelocity or volumetric fluid flow rate; and determining an adjustedvelocity or volumetric fluid flow rate using the at least one errorfunction and the measured velocity or volumetric fluid flow rate.
 2. Themethod of claim 1, wherein the steps of determining the measuredvelocity or volumetric fluid flow rate and producing the simulatedvelocity or volumetric fluid flow rate are performed for fluid flowconditions wherein the fluid flow is one or both of not fully developedor not well mixed.
 3. The method of claim 2, wherein the step ofproducing the simulated velocity or volumetric fluid flow rate includesinputting one or more fluid flow parameter values and iterativelyadjusting the one or more fluid flow parameter values to decrease amagnitude of the at least one error function.
 4. The method of claim 3,wherein the one or more fluid flow parameter values include at least oneof one or more fluid flow constituent flow rate values, one or morefluid flow constituent properties, or any combination thereof.
 5. Themethod of claim 1, wherein the step of determining the measured velocityor volumetric fluid flow rate using the SONAR flow meter includesmeasuring unsteady pressures relating to convective flow disturbances todetermine a measured characteristic velocity of the convective flowdisturbances; and wherein the step of producing the simulated velocityor volumetric fluid flow rate includes: determining a simulatedcharacteristic velocity of the convective flow disturbances; determininga difference between the measured characteristic velocity and thesimulated characteristic velocity; and adjusting a magnitude of the atleast one error function to decrease the difference between the measuredcharacteristic velocity and the simulated characteristic velocity. 6.The method of claim 1, further comprising: determining a measured fluidflow pressure drop across a length of the pipe; and producing asimulated fluid flow pressure drop across the length of the pipe usingthe CFD analysis device; wherein producing at least one error functionfurther includes using the measured fluid flow pressure drop and thesimulated fluid flow pressure drop.
 7. The method of claim 1, whereinthe step of determining the measured velocity or volumetric fluid flowrate using the SONAR flow meter includes determining the measuredvelocity or volumetric fluid flow rate using “N” number of SONAR flowmeters, where “N” is an integer equal to or larger than two; and whereinthe step of producing the at least one error function is based on themeasured velocity or volumetric fluid flow rate from each of the “N”number of SONAR flow meters and the simulated velocity or volumetricfluid flow rate.
 8. The method of claim 7, wherein each of the “N”number of SONAR flow meters is associated with a respective length ofthe pipe; the method further comprising: determining a measured fluidflow pressure drop across a second respective length of the pipe; andproducing a simulated fluid flow pressure drop across the secondrespective length of the pipe; wherein the step of producing the atleast one error function is additionally based on the measured fluidflow pressure drop and the simulated fluid flow pressure drop.
 9. Themethod of claim 1, further comprising controlling the fluid flow passingwithin the pipe with a control valve based on the adjusted velocity orvolumetric fluid flow rate.
 10. A system for measuring a velocity orvolumetric fluid flow rate of a fluid flow passing within a pipe,comprising: a SONAR flow meter configured to determine a measuredvelocity or volumetric rate of a fluid flow passing within a pipe; a CFDanalysis device configured to produce a simulated velocity or volumetricrate of the fluid flow passing within the pipe; and a processing unit incommunication with the CFD analysis device and the SONAR flow meter, theprocessing unit configured to produce at least one error function basedon the measured velocity or volumetric fluid flow rate and the simulatedvelocity or volumetric fluid flow rate, and configured to determine anadjusted velocity or volumetric fluid flow rate using the at least oneerror function and the measured velocity or volumetric fluid flow rate.11. The system of claim 10, further comprising: a first pressuredetector disposed at an upstream end of a length of the pipe; and asecond pressure detector disposed at a downstream end of the length ofthe pipe; wherein the first pressure detector and the second pressuredetector are configured to determine a measured fluid flow pressure dropacross the length of the pipe.
 12. The system of claim 11, wherein theCFD analysis device is configured to produce a simulated fluid flowpressure drop across the length of the pipe and the processing unit isconfigured to produce the at least one error function additionally basedon the measured fluid flow pressure drop and the simulated fluid flowpressure drop.
 13. The system of claim 12, further comprising anintentional pressure loss device disposed within the pipe between thefirst pressure detector and the second pressure detector with respect tothe fluid flow.
 14. The system of claim 13, wherein the intentionalpressure loss device is a control valve.
 15. The system of claim 11,further comprising “N” number of SONAR flow meters configured todetermine the measured velocity or volumetric rate of the fluid flowpassing within the pipe, where “N” is an integer equal to or larger thantwo; wherein the processing unit is configured to produce the at leastone error function based on the measured velocity or volumetric fluidflow rate from each of the “N” number of SONAR flow meters and thesimulated velocity or volumetric fluid flow rate.
 16. The system ofclaim 15, wherein each of the “N” number of SONAR flow meters isassociated with a respective second length of the pipe.
 17. The systemof claim 16, further comprising a plurality of pressure detectorsincluding the first pressure detector and the second pressure detector,the plurality of pressure detectors configured to determine the measuredfluid flow pressure drop by performing “M” number of differentialpressure measurements, where “M” is an integer equal to or larger thantwo; wherein the CFD analysis device is configured to produce asimulated fluid flow pressure drop corresponding to each of the “M”number of differential pressure measurements; and wherein the processingunit is configured to produce the at least one error function using themeasured fluid flow pressure drop and the simulated fluid flow pressuredrop.
 18. The system of claim 10, wherein the CFD analysis device isconfigured to produce the simulated velocity or volumetric fluid flowrate by inputting one or more fluid flow parameter values anditeratively adjusting the one or more fluid flow parameter values todecrease a magnitude of the at least one error function.
 19. The systemof claim 10, wherein the SONAR flow meter comprises multiple sensorarrays disposed around a full circumference of the pipe.
 20. The systemof claim 10, wherein the SONAR flow meter comprises multiple sensorarrays disposed around a circumferential portion of the pipe which isless than a full circumference of the pipe.